The covering cap of a steering wheel gas bag module is usually of plastic and is visible on the front face in the installed state of the module. The gas generator and the gas bag are inserted on the rear face into the container-shaped covering cap. A so-called gas generator carrier of sheet metal is fastened to the covering cap by means of rivets or hooks and forms the rear face of the covering cap which is to be closed after the insertion of the gas bag and the gas generator. The gas generator is fastened to this gas generator carrier and the entire module is attached to the steering wheel via this carrier. It is therefore obvious that the gas generator carrier must be constructed so as to be very stable and the connection between gas generator carrier and covering cap must withstand high tensile forces. On opening of the covering cap by the unfolding gas bag, in fact high forces are exerted onto the covering cap and hence onto the connection between covering cap and gas generator carrier.
The connections hitherto of gas generator carrier and covering cap, namely rivets and hooks, led to high pressures on the faces of the rivet- or hook apertures. The risk of the plastic covering cap tearing out was reduced by complicated undercuts to receive forces in the cap, which, however, were only able to be realized by costly injection tools. In addition, the rivets or hooks had to be placed as far away from the gas bag as possible and hence close to the rear face of the covering cap, so that a contact with the gas bag and a tearing of the gas bag by the rivets is avoided. This means, however, that the rivets had to be arranged very close to the rear edge of the covering cap, possibly even additional structural space was required in order to prevent a tearing out of the covering cap. The connection of covering cap and gas generator carrier by means of rivets or the bending of hooks is, in addition, very costly.